In many microfluidic systems for biological and chemical applications, there is often a need for a fast and complete mixing of various solutions in order to achieve the desired result. However, in micro geometry, the viscosity of the fluid may become significant and dominate the flow characteristics of the fluid resulting in a low Reynold's number and so laminar flow. As a result, mixing depends on diffusion rather than macro scale turbulent flow which is a slow molecular process. Microfluidic mixers are known, with the degree of interference between the mixing fluids sufficient when the fluids are of a similar viscosity. However, due to the limitations of prior art microfluidic mixing devices being able to adequately interfere with the fluids, there are generally inadequate where the respective viscosities of the fluids are substantially different.
It would therefore be advantageous to have a mixing device and method of operation of such a device that introduces greater interference between the fluids in order to better and more quickly achieve the desired degree of mixing.